1. Field of the Invention
The present invention relates to an improved method of metallic painting for motor vehicles and the like, in which an air atomized spray machine and a spin coating machine are used in combination.
2. Description of the Related Art
In metallic painting, such as top coating on car bodies, an air atomized spray machine has conventionally been used, because good alignment of metallic pigments, such as aluminum flakes, is achieved. In some applications, however, a bell-type spin coating machine is used in combination with a air atomized spray machine because of its high efficiency. The expression "metallic painting" used herein means painting using a paint containing brilliant pigments such as aluminum flakes or mica flakes.
It has been known that the finished appearance of a metallic paint, such as color shade and brightness, differs significantly between painting using an air atomized spray machine and painting using a bell-type spin coating machine.
A painting method by the combined use of an air atomized spray machine and a bell-type spin coating machine is disclosed, for example, in Japanese Patent Publication No. HEI 1-34102, which describes a painting method for eliminating differences or non-unformities in the finished appearance of metallic painting.
The disclosed technique, when a bell-type spin coating machine is used for metallic painting, is a method for finishing metallic painting, in which a surface that is to paint using a bell-type coating machine is painted using an air or airless spray machine before or after painting using the bell-type machine. The content of metallic pigments in the metallic paint applied using the air or airless coating machine is 30 to 90 percent by weight of metallic pigments contained in the metallic paint applied using the bell-type machine.
In this method, when an air atomized spray machine is used for painting, the content of metallic pigments in the metallic paint, compared to painting using a bell-type spin coating machine, is decreased to 30 to 90 percent by weight of metallic pigments contained in the metallic paint applied using the bell-type machine in order to eliminate color differences.
Although the known method for eliminating color differences by adjusting the content of metallic pigments is effective to some extent on the finished appearance, differ in hue or brightness occur, because this method produces a state as if the color were thinned before painting.
It is therefore an object of the present invention to provide a method for applying a metallic paint, in which painting using an air atomized spray machine and painting using a bell-type spin coating machine are combined to minimize color differences while maintaining the high painting efficiency of the bell-type spin coating machine.